Commutator Motor Research Articles

Mathematical model of transient processes of DC motor with permanent-magnet excitation

Permanet magnet DC motors ( PM DCM) have an advantage over electromagnetically excited commutator motors due to their better energy performance. The application of analytical methods to study PM DCM requires significant simplifications, and the use of field methods is quite labour-intensive. In our opinion, the use of electric and magnetic circuit methods makes it possible to achieve the accuracy of calculating the PM DCM that is sufficient for engineering needs. The purpose of the article is to develop a mathematical model of transient processes in PM DCM based on the use of the theory of electric and magnetic circuits. The article proposes an equivalent scheme for the magnetic circuit of PM DCM and a system of equations describing it. There are given equations for transient processes in PM DCM and an algorithm for their solution, which involves the integration of the solution of the system of equations of the magnetic state at each step. The proposed mathematical model of transient processes in PM DCM can be used to analyze these processes, as well as in design.

Commutator motor fault diagnosis using acoustic data with a transfer learning approach

Commutator motor fault diagnosis using acoustic data with a transfer learning approach

Determining the Switching Frequency of a Transistor Converter for a Traction Collector Motor

The purpose of this work is to determine the switching frequency of a transistor converter for a traction collector motor of a locomotive based on the criterion of permissible current ripple. The stated goal is achieved by solving the following problem: a methodology for determining the consideration of changes in motor parameters when calculating the switching frequency of the transistor converter is proposed. The peculiarity of the proposed approach is that it takes into account the degree of saturation of individual parts of the magnetic system of the electric motor. The most significant result is an increase in the accuracy of calculating the switching frequency by taking into account the change in the inductance of the commutator motor windings when the degree of saturation of the magnetic system changes. The switching frequency for a DC traction motor with a pulse converter is calculated. Two main operating modes of the electric motor are considered: with full magnetic flux and with weakened magnetic flux. As a result of calculations, it was established that the dependence of switching frequency on currents is nonlinear. For the operating mode of the electric motor with full magnetic flux, the switching frequency is determined taking into account the processes in the field winding circuits and in the armature circuit windings. The most important results are the determination of the switching frequency of the pulse converter for powering and regulating the traction motor in all operating modes. The proposed methodology allows the selection of transistor devices for the converter according to the switching frequency.

Thermographic fault diagnosis of electrical faults of commutator and induction motors

In this paper, the author proposes a fault diagnosis technique for the analysis of thermal images of commutator motors (CMs) and single-phase induction motors (SIMs). The aim of scientific research is to confirm the effectiveness of the proposed technique for the analysis of thermal images of electric motors. Original feature extraction methods: DAMOM (Differences of Arithmetic Mean with Otsu’s Method), DAM20HP (Differences of Arithmetic Mean with 20 Highest Peaks), DAMMH (Differences of Arithmetic Mean with Mean of the histogram), IB (Ignore Binarization). The Nearest Neighbor classifier and Long short-term memory (LSTM) classified feature vectors. The thermal imaging camera was moved 0–1 [m/s2] vertically, during the measurements. Thermal imaging measurements with shivering and analysis are a novelty for fault diagnosis methods. The following conditions of motors were analyzed: healthy commutator motor (HCM), broken rotor coil of the commutator motor (BRCoCM), shorted stator coils of the commutator motor (SSCoCM), healthy single-phase induction motor (HSIM), single-phase induction motor with shorted coils of auxiliary winding (SIMwSCoAW), single-phase induction motor with shorted coils of auxiliary winding, and main winding (SIMwSCoAWaMW). The proposed analysis was successful. The value of AMECM (Arithmetic mean of the efficiency of recognition) was equal to 100% for the analyzed states of the CM. The value of AMESIM was in the range of 95.33%–100% for the analyzed states of the SIM. The original perspective of the presented study is to develop techniques of thermal imaging diagnostics. Readers can learn about the subject of thermographic diagnostics of electrical motors. Readers also gain knowledge about the processing of thermal images. A literature review on the diagnostics of electric motors was also presented.

48-Volt Energy Efficient Domestic Appliances With Flux Switching Motor Drive System–Design, Simulation, and Comparison

Energy-Efficient domestic appliances are the need of the hour. This paper explores the importance of 48-Volt domestic appliances especially those operated with an electric motor drive system. Sixteen domestic appliances that are having a power range of 12 Watt – 1600 Watt are selected. These appliances are usually produced in very large volumes; therefore, one of the most important requirements is efficiency with moderate cost. Commutator motors are widely preferred for those applications in the present commercial market, which lags in efficiency, requires more space and, bulkier. Flux Switching Motor (FSM) is a new variant in brushless direct current (DC) motor, which has a combined advantage of commutator, Switched Reluctance and, Permanent Magnet Brushless DC Motors (PMBLDC). Complete simulation results with the FSM drive system have been carryout and the performance is compared with the commutator DC motor (DCM) and Induction Motors (IM). Simulation results support FSM drive system technology and novel insights follow from this quantitative comparison.

МОДЕРНИЗАЦИЯ КОЛЕСНО-МОТОРНЫХ БЛОКОВ ТЕПЛОВОЗОВ В УСЛОВИЯХ ИМПОРТОЗАМЕЩЕНИЯ

The paper considers problems of import substitution of parts for wheels and motors units for freight and shunting diesel locomotives with 1050 and 1250 mm wheels and it also considers a task of modernization of technically outdated assemblies. In result of the analysis the authors revealed that it is necessary to: 1) develop a new assembly of motor support bearings with the use of domestic parts; 2) create a new design of an electric traction motor suspension for the substitution of a spring suspension that has wearable parts; 3) organize a search for solutions for perspective diesel locomotives that are intended to operate on the Eastern polygon. For diesel locomotives with 1050 mm wheels the authors propose designs of a frame support traction drive equipped with flat rubber-metal elements and a traction drive with rigid support of an electric traction motor on wheel centres by the use of domestic bearings. Instead of the spring suspension the authors recommend to use suspensions with flat rubber elements and spherical rubber-metal mounting, which will provide interoperability of bogies with modified and unmodified electric traction motors. For perspective diesel locomotives with 1250 mm wheels the authors propose designs of two-axle bogies equipped with high-torque commutator motors and a traction drive with a frame support suspension of a traction motor and an axial gearbox.

A METHODOLOGY TO SELECT ASYNCHRONOUS TRACTION ELECTRIC DRIVE FOR INNOVATIVE METRO ROLLING STOCK

The paper deals with the justification of the need to use an asynchronous traction electric drive on the metro rolling stock. The advantages of using an asynchronous traction electric drive in comparison with a DC commutator motor drive are formulated. The characteristics of modern innovative metro rolling stock with asynchronous traction electric drive of domestic and foreign production are analyzed. Aspects of the choice of a variable frequency asynchronous traction electric drive for innovative rolling stock are formulated and the existing typical algorithm of such choice is given. The main reasons for the irrational choice of traction asynchronous electric drive for the metro rolling stock are considered and the consequences of such a choice are analyzed. It is proposed to improve the methodology for selecting a variable frequency traction asynchronous electric drive for the metro rolling stock in terms of such an important operational factor as the specific cost of electrical energy for traction. The rational parameters of the variable frequency asynchronous traction electric drive according to the proposed procedure for the specified characteristics of the metro rolling stock are specified. The reserves of energy savings for the given conditions due to the introduction of an asynchronous traction electric drive with rational parameters on the innovative rolling stock are determined. It is established that the efficiency factor of the asynchronous traction motor significantly affects the specific electric energy consumption for the metro rolling stock traction and operating costs.

PID controller in the steering unit with the Ackermann principle

The scientific article offers a model of a commutator motor control based on the study of actual data received from the shaft position sensor. As a result of theoretical research, the feedback control of the electric motor was realized. The tractor steering system was studied to adjust the steering shaft position correctly in real time. It should be noted that the error of angular velocity control was less than 2%.

Математические модели магнитоэлектрических вентильных двигателей

The mathematical models of converter fed permanent magnet motors written in the coordinate axes are considered. Owing to pulse-width modulation, the currents and voltages of the motors are assumed to be sinusoidal. In the models with two state equations, the stator current is represented only by its quadrature-axis component, and the variable load angle appears in explicit or implicit form. These equations are most close to the similar equations of dc commutator motors. Third-order equations contain both stator current components; the load angle in them is fixed as constant one or varies to maintain the unity power factor for an arbitrary load. The models constructed in the form of state equations of the appropriate order, which are implemented in the MathCad software, illustrate possible functional regimes of the motor and indicate the ways of their possible implementations using means known from the practice.

Unimodal electric motor-generator

The commissioning of nuclear power plants in Belarus sets out wide tasking for the efficient usage of electrical energy in various electrical systems, instruments and devices. Specifically, it concerns the stationary and special-purpose electric motors. At present, they use bipolar motors with a collector – the switch of the motor armature windings during its rotation. However, there is a completely different type of motors that does not require a collector – the unipolar electric motor-generator. Some of its properties allow it to be used where the commutator motor is unsuitable, for example, in explosive and fire hazardous environments (sparking on the collector is unacceptable), in precision devices where extreme smoothness and vibration lack are required, etc. Physico-mathematical foundations of the unipolar motor-generator (moving media electrodynamics, Lorentz force, unipolar induction, magnetohydrodynamics) are described in a number of monographs and textbooks, for example, in [1–4]. The purpose of this article is to pay attention to the technical feasibility of the unipolar motor-generator in a design with separated conductors in the rotor drum.

АНАЛИЗ ВОЗМОЖНОСТИ ПРИМЕНЕНИЯ АСИНХРОННЫХ ТЯГОВЫХ ЭЛЕКТРОДВИГАТЕЛЕЙ С РАЗЛИЧНЫМ ЧИСЛОМ ФАЗ

The paper analyses operational indicators of electric locomotives with commutator and induction motor traction motors. It is established that, due to the inherent limitations of the commutator motors, electric locomotives can work with rated power in speed range of 51.2–79 km/h, at maximum speed of 100 km/h power doesn’t exceed 68 % of rated. In order to increase the energy efficiency the authors have proposed to widen by several times the speed range at a constant rated power and reduce as much as possible operation at overload modes. Induction motors have significantly wider ranges for electromagnetic, thermal and mechanical loads. The calculation of losses in converter of phases and frequency for induction motors with various number of phases showed that total losses of three-phase motor reach 1.9 %, losses of motor with even number of phases doesn’t exceed 0.8 %. As a result, it is preferable to use traction motors with 8-phase winding.

Acoustic fault analysis of three commutator motors

Abstract Electrical motors are used in industry and in home appliances. They are important for people. Electrical motors convert electric energy into mechanical work. They generate acoustic signals. In this research the author uses signal processing methods and acoustic signals of two commutator motors of electric coffee grinders and one motor of an electric impact drill. A technique of fault detection of mechanical faults of three commutator motors is presented. Following acoustic signals of the first electric coffee grinder are measured and analysed: healthy, with one missing screw, with a rear faulty sliding bearing and faulty shaft, with a burned out motor (motor off). Following acoustic signals of the second electric coffee grinder are measured and analysed: healthy, with a slightly damaged rear sliding bearing, with a moderately damaged rear sliding bearing, motor off. Following acoustic signals are measured for the electric impact drill: healthy, slightly damaged front bearing, moderately damaged front bearing, motor off. An analysis of acoustic signal was carried out using the developed MSAF-RATIO-24-MULTIEXPANDED-FILTER-8 (Method of Selection of Amplitudes of Frequency Ratio of 24% Multiexpanded Filter 8 Hz) and k-means clustering. The obtained results are very good. A total efficiency of recognition is in the range of 95–96%.

COMPARATIVE ANALYSIS OF THE ACCURACY OF COMMUTATION CURRENT MODELS, WHICH TAKE INTO ACCOUNT THE PRESENCE OF SHORT-CIRCUITED TURNS OF THE ARMATURE WINDING

A modern strategy for locomotive maintenance is based on the operational diagnostics of their equipment. Currently, a large number of locomotives are equipped with DC electric motors. These locomotives will be operated in the short term. About half of the failures of DC electric motors are caused by the failure of the armature structure elements and, above all, the armature winding. Detection of the nature of damage to this winding and the extent of its damage reduces the time spent on repairing the motor. The large fleet of locomotives with DC commutator motors determines the relevance of the problem of diagnosing the armature winding. The greatest amount of information about the state of the winding contains the dependence of the commutation current of its sections on time. Existing publications have paid great attention to the development of competing or complementary models of such dependencies. However, solving the problem of quantitative comparison of the developed models still requires significant efforts. The object of the paper study is the error of modeling of commutation current, provided that some of the armature winding turns are short-circuited. The aim of the study is a comparative analysis of the existing models of this current. In order to achieve this goal, the tasks were solved, as follows: 1) to clearly distinguish between models, according to methods for determining the dependence of current on time; 2) to determine the degree of physical and mathematical correctness of each of these models; 3) to assess the conditions of existence and numerical values of the differences between these models. Comparison of models in terms of accuracy has shown that the best is the selection of a separate current model for each specific combination of two special parameters. These parameters describe the degree of shorting of the armature winding section. However, it is inconvenient that with different combinations of parameters, one has to operate with different mathematical expressions. The generalized model of commutation current gives the same expressions for all combinations of the specified parameters. However, this model should be enhanced to improve its accuracy in the field of large numerical values of parameters.

Fault Detection of Electric Impact Drills and Coffee Grinders Using Acoustic Signals.

Increasing demand for higher safety of motors can be noticed in recent years. Developing of new fault detection techniques is related with higher safety of motors. This paper presents fault detection technique of an electric impact drill (EID), coffee grinder A (CG-A), and coffee grinder B (CG-B) using acoustic signals. The EID, CG-A, and CG-B use commutator motors. Measurement of acoustic signals of the EID, CG-A, and CG-B was carried out using a microphone. Five signals of the EID are analysed: healthy, with 15 broken rotor blades (faulty fan), with a bent spring, with a shifted brush (motor off), with a rear ball bearing fault. Four signals of the CG-A are analysed: healthy, with a heavily damaged rear sliding bearing, with a damaged shaft and heavily damaged rear sliding bearing, motor off. Three acoustic signals of the CG-B are analysed: healthy, with a light damaged rear sliding bearing, motor off. Methods such as: Root Mean Square (RMS), MSAF-17-MULTIEXPANDED-FILTER-14 are used for feature extraction. The MSAF-17-MULTIEXPANDED-FILTER-14 method is also developed and described in the paper. Classification is carried out using the Nearest Neighbour (NN) classifier. An acoustic based analysis is carried out. The results of the developed method MSAF-17-MULTIEXPANDED-FILTER-14 are very good (total efficiency of recognition of all classes—TED = 96%, TECG-A = 97%, TECG-B = 100%).

Calculation of Commutator Curve in Steady-State Operation Mode of Traction Motor with Simple Lap Armature Winding

The article is focused on the applicable methods of the commutator curve calculation. This curve provides a basis for the evaluation of the flashover appearance tendency on a commutator. It is reported that such methods demonstrate either its limited applicability, which is determined by its narrow focus on the certain kinds of commutator motors, or incapacity to provide required calculation accuracy. The basis for the calculation method presented in the article is numerical differentiation of the curve of coil flux linkage versus its relative angular position. Usage of the proposed method allows for the good convergence of the calculated bar-to-bar voltages with the experimental ones.

Выбор оптимальной конструкции электродвигателя привода пильгерстана для технологии изготовления бесшовных труб

This paper dwells upon optimizing the design of motors for pilger mills making seamless pipes of large diameter. The options are grouped into four types: high-speed motor with a reduction drive; low-speed motor, no reduction drive (replaces the existing motor); a motor that uses the flywheel as the rotor of another motor; no flywheel, a motor of equivalent inertial mass used instead. This research applies ANSYS Electronics Desktop: special software for computing electric machines which employs finite-element analysis. The options are compared against each other. Energy indicators coupled with a minimum use of active materials is the criterion applied to choose the best option. The replace the existing obsolete DC commutator motor, the paper proposes a drive based on a brushless claw-pole permanent-magnet motor that is more reliable thanks to contactless current feed while also using less copper and offering better energy indicators due to zero excitation loss.

Recognition of Acoustic Signals of Commutator Motors

Most faults can stop a motor, and time is lost in fixing the damaged motor. This is a reason why it is essential to develop fault-detection methods. This paper describes the acoustic-based fault detection of two commutator motors: the commutator motor of an electric impact drill and the commutator motor of a blender. Acoustic signals were recorded by a smartphone. Five states of the electric impact drill and three states of the blender were analysed: for the electric impact drill, these states were healthy, damaged gear train, faulty fan with five broken rotor blades, faulty fan with 10 broken rotor blades, and shifted brush (motor off); for the blender, these states were healthy, faulty fan with two broken rotor blades, and faulty fan with five broken rotor blades. A feature extraction method, MSAF-RATIO-27-MULTIEXPANDED-4-GROUPS (Method of Selection of Amplitudes of Frequency Ratio of 27% Multiexpanded 4 Groups), was developed and used for the computation of feature vectors. The nearest mean (NM) and support vector machine (SVM) classifiers were used for data classification. Analysis of the recognition of acoustic signals was carried out. The analysed value of TEEID (the total efficiency of recognition of the electric impact drill) was equal to 96% for the NM classifier and 88.8% for SVM. The analysed value of TEB (the total efficiency of recognition of the blender) was equal to 100% for the NM classifier and 94.11% for SVM.

Acoustic-Based Fault Diagnosis of Commutator Motor

In the paper, the author presents acoustic-based fault diagnosis of a commutator motor (CM). Five states of the commutator motor were considered: healthy commutator motor, commutator motor with broken rotor coil, commutator motor with shorted stator coils, commutator motor with broken tooth on sprocket, commutator motor with damaged gear train. A method of feature extraction MSAF-15-MULTIEXPANDED-8-GROUPS (Method of Selection of Amplitudes of Frequency Multiexpanded 8 Groups) was described and implemented. Classification methods, such as nearest neighbour (NN), nearest mean (NM), self-organizing map (SOM), backpropagation neural network (BNN) were used for acoustic analysis of the commutator motor. The paper provides results of acoustic analysis of the commutator motor. The results had a good recognition rate. The results of acoustic analysis were in the range of 88.4–94.6%. The NM classifier and the MSAF-15-MULTIEXPANDED-8-GROUPS provided TERCM = 94.6%.

High-Frequency Electric Shearing Unit for Sheep

A comparative analysis of sheep-shearing machines has been performed. Advantages and disadvantages of shearing machines with a single-phase commutator motor compared to a three-phase asynchronous electric motor with a short-circuited rotor are identified. An individual electric shearing unit with the improved converter and upgraded cutting machine with a vertical push mechanism is offered. This assembly equipment increases the efficiency of shearing the sheep due to the improved characteristics of the converter and the working parts of the shearing machine. The frequency converter has an energy saving function reducing the energy losses. The weight of the improved converter compared to the prototype is decreased by 2.1 kg. The vertical push mechanism gives a threefold reduction in the uneven pressing of the knife to the comb in a sharing machine. Comparative analysis of sheep-shearing machines has been performed. Advantages and disadvantages of shearing machines with a single-phase commutator motor compared to the three-phase asynchronous electric motor with a short-circuited rotor are identified. An individual electric shearing unit with the improved converter and upgraded cutting machine with a vertical push mechanism is offered. This assembly equipment increases the efficiency of shearing the sheep due to the improved characteristics.

Vibration‐Based Fault Diagnosis of Commutator Motor

This paper presents a study on vibration‐based fault diagnosis techniques of a commutator motor (CM). Proposed techniques used vibration signals and signal processing methods. The authors analysed recognition efficiency for 3 states of the CM: healthy CM, CM with broken tooth on sprocket, CM with broken rotor coil. Feature extraction methods called MSAF‐RATIO‐50‐SFC (method of selection of amplitudes of frequencies ratio 50 second frequency coefficient), MSAF‐RATIO‐50‐SFC‐EXPANDED were implemented and used for an analysis. Feature vectors were obtained using MSAF‐RATIO‐50‐SFC, MSAF‐RATIO‐50‐SFC‐EXPANDED, and sum of RSoV. Classification methods such as nearest mean (NM) classifier, linear discriminant analysis (LDA), and backpropagation neural network (BNN) were used for the analysis. A total efficiency of recognition was in the range of 79.16%–93.75% (TV). The proposed methods have practical application in industries.